I'll let others explain how this topic relates to me teaching art class. All I know is that I'm interested in the medical disorder Agnosia, Prosopagnosia in this situation. My non-medical definition: Agnosia deals with the inability to recognize objects that the average person would be able to recognize. The subtype of prosopagnosia deals with the inability to recognize a people's faces who would ordinarily be recognized.
Several days ago, I saw the House episode "Adverse Effects" that highlighted this disorder for me. The episode deals with a painter (played by Breckin Meyer, who starred in Road Trip) who unknowingly distorted a portrait of a commissioned piece.
Just a while ago, I finished watching a PBS NewsHour special that had an interview with Chuck Close, the American photo-realist (arguable) painter/photographer. While I knew that he was a paraplegic and suffered from a learning disability, I had no idea that he too suffered from prosopagnosia. This seems to help explain his fascination with the characteristics of the face.
After looking it up, I also learned that Jane Goodall also has this disorder.